1. Field of the Invention
The present invention relates to an information storage and retrieval system which permits storage, retrieval and display of information such as documents, drawings, photographs and the like in such a manner in which common users can easily manipulate the system for the storage and/or retrieval of information.
2. Description of the Prior Art
Heretofore, management of a data base which permits storage and retrieval of an enormous amount of information has been relied on by those skilled in the art. The information is available to the end user only through the medium of experts. However, in accompaniment to the development of small size storage devices of a large capacity such as optical disks, there are realized document filing systems for office use which can be directly manipulated by the end users. Further, word processors have increasingly come into wide use. Under the circumstances, there is an increasing tendency that a large amount of documents are stored in electronic devices.
Heretofore, items, such as documents, are managed in tabular form listing bibliographic data such as identification names, titles and author's names attached to the documents, and attempts have been made to facilitate the retrieval of information by assigning keywords or classification codes thereto. Nevertheless, there arise problems mentioned below.
In most of the computer file systems, the file management is performed with the aid of identification names (each composed of ca. 20 characters). However, difficulty is often encountered in naming the document or file so that it can be readily recalled. Besides, searching the file on the basis of the character string which constitutes the name while inferring the contents from the name is an extremely difficult job even for the user who has prepared the name himself.
Since the bibliographic data are objective items, registration thereof can be easily made. However, there scarcely arises the situation in which the bibliographic data are made use of as means for retrieval. Utilization of the bibliographic data as the aid for the retrieval is restricted to the rare case in which the document to be retrieved is clearly known to the user as the source or reference literature.
In most cases of the retrieval of documents, the title ambigously memorized by user or the contents thereof provides a clue for the retrieval. To this end, keywords and classification codes are employed. However, difficulty is encountered in assigning the keywords or classification codes to the documents upon registration thereof. In other words, it is difficult to determine the keyword which makes it possible to retrieve properly the associated document later on. By way of example, it is assumed that many keywords are attached to a document so that it can be retrieved, as viewed from various perspective. This however means that a number of keywords which are useless for retrieval are employed. If the number of the keywords is decreased, uncertainty arises as to the correct selection for retrieval. In the data base for literatures, preparation and allocation of the keywords have heretofore been relied on by those skilled in the art.
Moreover, difficulty is often encountered in recalling the keyword itself. By way of example, upon preparation of the retrieval formula composed of the keywords for the retrieval of a document, literatures having a resemblance to the desired one are searched out from a general list for picking up their keywords, which are then referred to for determining the keywords possibly allocated to the desired document. Such procedure is not rare and tells how difficult it is to recall the keyword.
In the case of filing documents through classification, ambiguity of the taxonomic tree (hierarcal tree) as well as confusion of the taxonomic trees (i.e. multiple classifications of one document) provide problems. Further, standards for the classification vary as passes. A span of several years will make the classification standards useless, giving rise to another problem.
Under the circumstance, easy management and retrieval of information for the user provide extremely important problems remaining to be solved in the hitherto known document filing systems.
As n attempt to cope with the above problems, there has been proposed a method of diagraming the retrieval conditions and deriving a formal query formula for the retrieval by using natural language, as disclosed in J. F. Sowa's "Cohceptual graphs for a Data Base Interface" IBM J. Research and Development, Vol. 20, 1976, p.p. 336-357. Furthermore, a method of assisting creation of the conditional formula for retrieval by presenting knowledge concerning the contents of a data base from a computer is known, as disclosed in F. N. Tou et al's "RABBIT: An Intelligent Database Assistant", Proceedings of National Conference of AAAI, 1982, p.p. 314-318. These methods are intended only for assisting the retrieval from the data base. No teachings are disclosed as to the assistance of storage of information for the updating purpose.
In the filing of documents by the end user, registration of new documents as well as maintenance of the file system (e.g. reexamination as to pertinency of classification) is important for realizing the facilitated retrieval. The approaches mentioned above do not meet this requirement.
Finally, the retrieval is accompanied by still another problem. Namely, no measures are available for re-examining the old information from the view point of a new concept which has not yet been clearly defined at the time the old information was stored or for retrieving from the new point of view. By way of example, there often occurs such case in which classification is to be modified from the new viewpoint or in a manner specific to the user himself after lapse of several years. In this way, possibility of rearrangement of information as well as alteration of retrieval also provide important factors for enhancing the easy usability of the information storage and retrieval system.